A method for computing the optical path length in gradient-index media is presented. A comparison with other methods shows that this is more accurate and faster. This method is based on a series expansion of the refractive index of the medium as a function of a suitable ray-trace parameter.
© 1985 Optical Society of America
Anurag Sharma, "Computing optical path length in gradient-index media: a fast and accurate method," Appl. Opt. 24, 4367-4370 (1985)